I think this question has to be split into two different parts.
Is it safe? YES without a doubt. But remember the primary safety as always is the shooter him/herself.
The next question should therefore be: Is the condition One carry of any SA handgun, the 1911 in particular likely to give rise to secondary criminal charges of negligence and or concurrent civil charges by the nature of the weapon itself? That depends. Mostly it depends on the jurisdiction and political climate. An ambitious prosecutor looking to make a name for himself might find it easier to support a more nebulous charge of negligence (manslaughter) and depend on the ignorance of a jury to make the case against the gun rather than the shooter or circumstances. I have seen this done many times here in Miami-Dade county over the last 25 years. Many folks won't know to have an "expert witness" to dispell gun myths and even if they do know, can't afford to have Mas Ayoob or one of the other heavyweights come down and defend the "gun." Juries are chosen for unifomity in ignorance.
My point is, if you know you live in a liberal, anti-gun jurisdiction, why take the chance with a 1911 SA? I practice what I preach. Although I have two fine 1911's, I no longer carry them for exactly this reason.